The two French students found stabbed to death after a fire at a London flat may have been the victims of a bungled burglary, police said today.

Games consoles belonging to Laurent Bonomo and Gabriel Ferez are believed to have been stolen from the bedsit in New Cross, south-east London, where their bodies were discovered.

Police are also trying to establish whether bank cards belonging to the students were also stolen.

The bodies of the 23-year-old victims were found in the ground-floor flat on Sunday night. They had been bound, gagged and stabbed a total of more than 200 times in what detectives described as one of the most horrific attacks they had ever seen.

Police said one line of inquiry was that the pair were killed during a burglary. A spokesman said they hoped to make an arrest "sooner rather than later". Officers said they were following up on about 25 calls received in connection with the case.

Detective Chief Inspector Mick Duthie, who is leading the investigation, said: "We are keen to hear from anyone who has recently been offered a laptop and two personal game consoles, or knows someone who has unexpectedly come to have them."

Scotland Yard said the flat had been broken into six days earlier, when the laptop was stolen. It is understood the thief was disturbed by one of the students.

Duthie said: "A black Packard Bell laptop was taken during a burglary that took place between 5am and 6am on the morning of June 23. Someone entered the living room of 12 Sterling Gardens and stole the computer. Bonomo said he was in the shower when he heard a suspicious noise. He found the window of his living room forced open and his laptop was stolen.

"The search of the address is not yet completed, but we have established that two Sony PSPs are missing and believe they were taken during the incident on Sunday when the two men were killed."

Police said the attack did not appear to have been the work of professionals. "I would say it was a frenzied, horrible, horrific attack. I imagine it would take some considerable amount of time to inflict the nature of the injuries," Duthie said.

Detectives said there was no evidence of forced entry, and a set of stolen keys may have been used, enabling the attacker to surprise his victims. A white male was seen running from the address moments after it exploded in flames, but he has not been identified.

Duthie said "If you were visiting a friend or a colleague in this area, if you were passing through, please let me know and I can eliminate you from the inquiry. The longer it takes to find you the more my suspicion rises."

Detectives said there was no evidence of forced entry, and a set of stolen keys may have been used, enabling the attacker to surprise his victims. A white male was seen running from the address moments after it exploded in flames.

A pathologist documented 243 separate injuries to the badly burned bodies, with Bonomo suffering 80 wounds after he died. It is believed the two men may have been tortured for several hours.

Bonomo and Ferez were promising research students who had been working on a DNA research project at Imperial College, London.

Bonomo's fiancee, Mary Bertez, has vowed to "avenge" his death. She wrote a Facebook message yesterday saying: "My love, we were always together but unfortunately I wasn't there that evening. I will never stop thinking about you for a second. I had 10 months of a happiness I had never experienced until then. I will give all the required information to the investigation, my dear, so you can be avenged."